Pressure booster



Dec. 5, 1950 F. M. SLATER 2,532,679

PRESSURE BOOSTER Filed April 11, 1944 HIS ATTORNEY.

laten tecl Dec. 5, 1950 PRESSURE BOOSTER Fred M. Slater, Phillipsburg, N. 3., assignor to Ingersoll-Rand Company, New York, N. Y., a corporation of New Jersey Application April 11, 1944, Serial No. 530,525

3 Claims.

This invention relates to fluid compressors, and more particularly to a pressure booster the compressing element of which is subjected directly to pressure fluid for actuating it.

One object of the invention is to enable the pressure value of a fluid to be conveniently and expeditiously increased.

Another object is to provide a light weight pressure booster of simplified and rugged. construction that is readily transportable and may be operated and maintained with a minimum of expense.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference numerals refer to similar parts,

Figure l is a side elevation of a pressure booster constructed in accordance with the practice of the invention and showing it attached to a drill column, the column being partly broken away,

Figure 2 is a longitudinal elevation, partly broken away, of an enlarged view ofthe booster showing the movable elements of the booster in certain limiting positions which they may assume in practice, and

Figure 3 is a similar View showing the movable parts of the booster in other limiting positions.

Referring more particularly to the drawings, designates the pressure booster and 2! a drill column to which the discharge end of the booster is connected by a conduit 22.

The drill column 2!, which is shown merely as an example of a device requiring pressure fluid of a higher value than associated pressure fluid actuated mechanisms, comprises a cylinder 23 having a foot piece 24 to rest upon a supporting surface (not shown) as for example thefloor of a mine tunnel. The cylinder occupies a vertical position and contains a piston 25 the rod 26 of which projects slidably from the upper end of the cylinder 23 and is pointed for engagement with an overlying surface (not shown). cylinder 23 serves as a support for a column arm 21 which 'may be secured thereto in any well known manner and carries clamping mechanism 28 commonly employed for securing rock drilling mechanism 29 to the arm 21.

The drilling mechanism is illustrated as being of the drifter type comprising a shell 36 that is gripped by the clamping device 28 and supports, slidably, a rock drill 3! which may be actuated endwise of the shell 39 by a feed screw 32.

The rock drill 3! is of the fluid actuated type and accordingly has a supply conduit 33 that is The shown connected to a conduit 34 leading from a source of pressure fluid supply (not shown) to the booster 20.

The booster 2B, constructed in accordance with the practice of the invention, comprises a cylinder 35 having a bore consisting of an enlarged portion and a reduced portion that, respectively, constitutes a power chamber 36 and a compression chamber 3?. The outer end of the power chamber is closed by a head 38 that is secured to the cylinder 35 by screws 39 and has an aperture 40 that is threaded at its outer end to accommodate an end of the conduit 34. Similarly, a plate 41 overlies and is secured to the opposite end of the cylinder by screws 39 and has an aperture 42 the outer end of which is threaded to accommodate an end of the conduit 22.

Communication is afforded between the aperture 42 and the compression chamber 3'! by a passage 43 in the plate 4! and an end wall 44 of the chamber 3'5, and a spring-pressed check valve 45 seated against the outer surface of the wall 44 controls communication between the aperture 42 and the compression chamber.

The fluid intended to be compressed by the booster is of the same pressure value as that used for operating the rock drill 3!, and the booster 20 is accordingly provided with a supply passage 46 that leads from the aperture 05 through the head 38, the cylinder 35 and the plate at and opens into the end of the compression chamber 31. Communication between the supply passage and the compression chamber is controlled by a spring-pressed check valve 4 arranged in the end wall 45 and seating against the confronting surface of the plate 4 l.

The admission of pressure fluid to the power chamber 36 to act against the enlarged portion or head 58 of the piston :19 in the chambers is controlled by automatic valve mechanism 50 located adjacent the compression chamber 31. The valve chest 5| of said valve mechanism contains a bushing 52 the interior of which constitutes a valve chamber 53 for the accommodation of a valve 54. The outer end of the bushing 52 lies flush with the adjacent end of the cylinder and is sealed by a plug 55 having an external flange 56 that extends into the plate a: and overlies the end of the bushing.

The pressure fluid distributed to the power chamber 36 by the valve 5 3 enters the intermediate portion of the valve chamber 53 from the supply passage 56 through a passage 5'1 and flows from the valve chamber 53 to the outer end of the power chamber through an inlet pas sage 58 in the cylinder 35. Pressure fluid is admitted to only the outer end of the power chamber 36 for actuating the piston, the opposite end of the power chamber being in constant communication with the atmosphere through a port 59, in the end of the cylinder, an annular groove 60 in the outer surface of the bushing 52 and an atmospheric port 6| in theadjacent end of the valve chest The inlet passage 58 opens into the valve chamber 53 at a point forwardly of the passage 51 and serves also to convey exhaust fluid from the power chamber 36 to the valve chamber. Such exhaust fluid passes from the valve cham? ber to the atmosphere through an exhaust port 62 located between the inlet passage 58 and the power chamber 36.

The valve chamber 53 consists of three portions 63, 64 and 65 the diameters of which increase in size in the order named, and the valve 55 has corresponding portions 56, 61 and 68 to lie, respectively, Within the portions 63, 64 and 65. The opposed ends of the enlarged portion or head 68 constitute actuating surfaces 63 and 10, the latter being located at the end of the valve to be subiected intermittently to pressure fluid conveyed thereto by a kicker passage ll opening into the power chamber 38 at a point to be uncovered by the piston head 48, at or near the end of its working, stroke.

The actuating surface 69, located at the other end of the enlarged portion 68 of the valve, is likewise subjected intermittently to pressure fluid conveyed thereto by a kicker passage i2, leading from the compression chamber 3'! through the cylinder, and by a passage in the bushing opening into the inner end of the portion 65 of the valve chamber. The passa e I2 opens into the compression chamber 3'? at a point to be uncovered by the piston near or at the end of its suction stroke.

Preferably the outer and inner ends of the enlarged portion 65 of the valve chamber are vented to the atmosphere through ports 73 and 14, respectively, of somewhat smaller flow areas q than the passages H and T2 to permit of the immediate, although restricted, exhaust of fluid from said enlarged portion 65 after the valve has been thrown to its limiting positions.

The valve 55 is held in position for admitting pressure fluid into the inlet passage 53 by the pressure fluid passing through the valve chamber from-the passage 5? to the passage 53. Such pressure fluid acts against an external shoulder 75 at the juncture of the portions 6 5 and $1 of the valve, and in the outer surface of the said por' tion 55, forwardly of the shoulder 75., is an annular groove it? to afford communication between the passages 5! and 5%.

The valve 55 is held in its other limiting position by pressure fluid. flowing from the passage 5'! through radial ports H, in the valve, into abore 18 extending part way through the valve from the enlarged end thereof. The pressure fluid thus admitted into the bore 18 acts against a holding surface, or surfaces, H9 in the bore and an end surface 85) of a stem 85 on the plug 55 extending into the bore "it. At the inner end of the bore it is a port 82 to register with the exhaust port 82 for exhausting fluid from the bore 78.

A suitable manually operable valve device 3.3 is placed in the conduit 3! to control the supply of pressure fluid to the booster 23, and a throttle valve 84 is shown arranged in the foot piece 24 for controlling the flow of presssure fluid from the conduit 22 into the cylinder 23 of the drill column.

In practice, whenever it is intended to operate the booster and assuming that the movable parts thereof, such as the piston 49 and valves 45, 41 and 54, occupy the positions shown in Figure 3 of the drawings, the valve 83 is opened to communicate the aperture 43 with pressure fluid supply. Pressure fluid then flows through the supply passage 48 past the check valve 41 into the compression chamber 3'! against the smaller end of the piston 39 and moves the piston outwardly to the end oi its suction stroke. At the same time pressure fluid will flow from the compression chamber through the passage 43 and the conduit 22 into the cylinder 23 and extend the column between the supporting surfaces.

When the piston 49 approaches the end of its suction stroke it uncovers the kicker passage 12 and pressure fluid then flows from the compression chamber 31; through the passage 12 against the actuating surface 69 and moves the valve 54 in the direction or the enlarged end of the valve. chamber, In this position of the valve the passage 5? will be in communication with the pas-s sage 53 through the annular groove 16. and pressure fluid will then flow through these channels into the power chamber 36 to drive the piston lfl on its compression stroke. During this time the valve will be held stationary by the pressure fluid flowing across the holding surface 15.

When the piston A9 approaches the end of its compression stroke the head 48 uncovers the. kickerpassage ii and pressure fluid will flow through said kicker passage from the power chamber against the actuating surface iii and move the valve 54 in the direction of the small end of the valve chamber 53. In this position the valve will cut-off communication between the passages 51 and 58, and the port Ti will be in direct communication with the passage 5'! so that pressure fluid will flow into the bore 18 to hold the valve momentarily stationary.

In this new position of the valve the passage 53 will be in communication with the exhaust port 52 through the annular grooves '55 and fluid will exhaust from the power chamber through these channels to the atmosphere. At the same time the piston will again be returned to the end of itsv suction stroke by the pressure fluid flowing into the compression chamber 3?. This operation may continue until a pressure of the required value has been attained Within the cylinder 23 to assure against the shifting of the drill column by the thrust and the vibration of the rock drill during its operation.

In practice the present invention has been found to be particularly desirable for use in instances where one or more of a number of pressure actuated mechanisms require power of a value greater than that required by the other mechanisms. In such case the booster may be quickly connected to the pressure fluid supply line and to the mechanism requiring the higher pressure and be set in operation to perform its boosting function automatically as long as the booster remains in communication with the source of power supply.

I claim:

1. A pressure booster, comprising a casing having a bore to define a power chamber and a compression chamber of smaller diameter than the power chamber, a piston in the chambers, a supply passage in the casing for supplying pressure fluid to the compression chamber for compression to a higher value and to actuate the piston in one direction, a discharge passage in the casing for the compression chamber, check valves to control the passages, inlet and exhaust passages in the casing for the power chamber, a valve to control the inlet and exhaust passages and having opposed actuating surfaces, and crossed kicker passages in the casin having their inlet ends covered and uncovered by the piston to valve pressure fluid intermittently to the actuating surfaces for actuating the valve.

2. A pressure booster, comprising a casing having a bore to define a power chamber and a compression chamber of smaller diameter than the power chamber, a piston in the chambers, a supply passage in the casing for supplying pressure fluid to the compression chamber, a discharge passage for the compression chamber, check valves to control the said passages, inlet and exhaust passages in the casing for the power chamher, a valve to control the inlet and exhaust passages and having opposed actuating surfaces, a kicker passage in the casing covered and uncovered by the piston to valve pressure fluid from the power chamber to one actuating surface for moving the valve in one direction, and a second kicker passage in the casing covered and uncovered by the piston to valve pressure fluid from the compression chamber to another actuating surface for moving the valve in an opposite direction.

3. A pressure booster, comprising a casing having a bore to define a power chamber and a compression chamber of smaller diameter than the power chamber, a piston in the compression chamber having a head lying in the power chamber, supply and discharge passages for the compression chamber, check valves to control the passages, an inlet passage in the casing for conveying pressure fluid into and exhaust fluid from the power chamber, a valve in the casing to control the inlet passage and having a pair of opposed actuating surfaces, a kicker passage in the casing for conveying pressure fluid from the power chamber to one actuating surface to throw the valve to a position to communicate the inlet passage with the atmosphere and opening into the power chamber at a point to be uncovered by the head at the end of the compression stroke of the piston, and another kicker passage in the casing for conveying pressure fluid from the compression chamber to the other actuating surface for throwing the valve to a position to admit pressure fluid into the inlet passage and opening into the compression chamber at a point to b uncovered by the piston at the end of the suction stroke of said piston.

FRED M. SLATER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

